<!DOCTYPE html>
<html>
<head>
	<title></title>
</head>
<body>

<script type="text/javascript">
	
const foo = {};
foo.test = 1;
let kk = 2;
foo.test1 = kk;
console.error(foo.test);
console.error(foo.test1);
kk = 3;
console.error(foo.test1);
foo.test = 3;
console.error(foo.test);

</script>

</body>
</html>